CVE-2021-3490
Public on 2021-06-04
Modified on 2024-03-01
Description
The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).
Severity
CVSS v3 Base Score
See breakdown
Affected Packages
Platform | Package | Release Date | Advisory | Status |
---|---|---|---|---|
Amazon Linux 1 | kernel | Not Affected | ||
Amazon Linux 2 - Core | kernel | Not Affected | ||
Amazon Linux 2 - Kernel-5.15 Extra | kernel | Not Affected | ||
Amazon Linux 2 - Kernel-5.4 Extra | kernel | Not Affected | ||
Amazon Linux 2 - Kernel-5.10 Extra | kernel | 2022-01-20 | ALAS2KERNEL-5.10-2022-001 | Fixed |
Amazon Linux 2 - Kernel-5.10 Extra | kernel | 2022-01-20 | ALAS2KERNEL-5.10-2022-002 | Fixed |
Amazon Linux 2023 | kernel | Not Affected |
CVSS Scores
Score Type | Score | Vector | |
---|---|---|---|
Amazon Linux | CVSSv3 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
NVD | CVSSv2 | 7.2 | AV:L/AC:L/Au:N/C:C/I:C/A:C |
NVD | CVSSv3 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |